A video signal of an image captured by a video camera is transmitted to a video switcher or the like through a transmission cable. However, if such an apparatus is installed in a remote location, it is difficult to transmit the electrical signal without attenuating it. For this reason, long-distance transmission is performed by converting an electrical signal into an optical signal on the video camera side, transmitting this optical signal through an optical transmission cable, and converting the optical signal into an electrical signal on the remote apparatus side (see Japanese Unexamined Patent Application Publication No. 2006-191161).